FOSSIL CYCADEAN TRUNKS FROM WYOMING 255 



well worth a careful study. I am at the present time making a 

 special study of the Jurassic of Wyoming contemplating a 

 monograph on the subject as soon as it is possible to complete 

 the work. If you wish I can go to the field and give you an 

 absolute section of the bed." 



In another letter dated November i, 1898, he makes the fol- 

 lowing more specific statement : 



*'A section through the locality will be about as follows : 



Triassic red sandstone, 1000 feet. 



Lower Jurassic (marine), 200 feet. 



Upper Jurassic (fresh water), 225 feet. 



Dakota conglomerate, from 50 to 200 feet. 

 Your Black Hills section reminds me of the Big Horn Basin 

 country where I found beds that I could not place in the Dakota. 

 In no instance in the section given have I detected any non- 

 conformability, although I anticipate that such exists between 

 the Jurassic and Dakota." 



I spent the latter part of November of that year at the Yale 

 Museum describing the new material that Professor Marsh had 

 acquired since my visit in June. This included the two speci- 

 mens received from Mr. W. H. Reed from the Jurassic of Wyo- 

 ming and I took as full notes on them as possible. It was appar- 

 ent at a glance that they had nothing to do with the Black Hills 

 cycads, and that they were very different from anything that I 

 had seen either in this country or in Europe. In some respects 

 they resembled the specimens from the Purbeck beds of the Isle 

 of Portland, especially the small ones that I saw there in 1894, 

 and of which I obtained 20 specimens for the U. S. National 

 Museum. This, however, had less to do with their botanical 

 than with their mineralogical character — their light color, soft 

 ashy constitution, and especially their obviously partially cal- 

 careous nature. 



PERSONAL FIELD WORK. 



I naturally had a great curiosity to visit these beds and study 

 their geological position, and I was so fortunate as to make an 

 arrangement with Professor Knight to meet him on September 

 ist, 1899, at Laramie, Wyoming, and have his company and 

 guidance to the locality. We proceeded to Medicine Bow, 

 where he had an outfit in readiness to take us to the Freezeout 



